Evaporating-pan.



PATENTED MAR. 10, 1903. E. R. SHAW. EVAPORATING PAN.

APPLICATION FILED rm. 2. 1901.

N0 MODEL.

3 SHEETS-SHEET 1.

No. 722,636. PATENTED MAR. 10, 1903. E. R. SHAW. EVAPORATING PAN.

APPLICATION FILED FEB. Z. 1901.

NO MODEL. 2 SHEETS-SHEET 2.

UNITED STATES HATENT rFIcE.

ELTON R. SHAW, OF ONTARIO, CALIFORNIA.

EVAPORATlNG-PAN.'

SPECIFICATION forming part of Letters Patent No. 722,636, dated March10, 1903.

Application filed February 2, 1901. Serial No. 45,669. (No model.)

To all whom it may concern:

Be it known that I, ELTON R. SHAW, a citizen of the United States,residing at Ontario, in the county of San Bernardino and State ofCalifornia, have invented an Evaporating- Pan, of which the following isa specification.

My invention relates to improvements in evaporating-machines in whichthe film system of evaporation is employed; and the. object of myinvention is to provide a continuous concave curved surface upon whichthe film of evaporating material is to be disposed and upon which acurrent of the air-absorbent medium may be made to continuously impingedirectly upon the film so as to break up and remove the protecting airfilm that covers the liquid film in order to effect a more thorough,intimate, frictional, and continuous contact and repetition of suchcontacts with the surface of the liquid film that has been formed or isbeing continuously formed and reformed upon the curved surface mentionedand whereby the liquid under treatment is carried progressively thereonwhile being continuously exposed in the form of a thin film from theinlet or charging point of the apparatus to the outlet or dischargingpoint in a regular and positive manner, so as to give full and completecontrol over the liquid under treatment during the entire operation. Theliquid under treatment moves continuously in one direction under theinfluence of gravity alone, and the air moves in an opposite directioncontinuously under force of pressure, preferably mechanical. I attainthese objects by the mechanism illustrated in the accompanying drawings,in which- Figure l is a side elevation of the evaporator,part sectional;Fig. 2, an end elevation of the same, part sectional; Fig. 3, a planview of the same,part sectional; and Fig. 4, an ele vation of theevaporator within a housing.

Similar letters refer to similar parts throughout the several views.

A is a horizontal unilocular pan, spirally projected, composed of sheetmetal or other suitable material, preferably provided with flanges A Aat both sides of the pan for the purpose of preventing the overflow ofliquid charges therefrom. The outer end of this pan'A is formed into atrough-like receptacle running the entire width of the pan and designedto be charged with and emptied of a certain amount of the liquid to beevaporated at each revolution of the apparatus when the pan reaches theproper point for that purpose and automatically.

B B are hollow hubs provided with spokes B B. The pair of hubs and thespokes of each are rigidly connected and held together and equallyspaced from each other by means of the tie-bolts B and thespacing-thimbles B or other suitable means, the spiral pan being placedbetween them and secured to and held in position by means of the saidhubs and spokes. The pan-body is suspended in a horizontal position byor carried upon the supporting-frames O C. The hollow hubs B B rest incradles formed by the car-wheels O and the axle O on each side of theapparatus. Provision is made for the discharge of the liquid from theinner end of the spiral pan when it reaches that point by way of thecontracted and tapered tubular inner end of the spiral pan at D, theprojection of the pan at that point extending through and out of thehollow hub B at the outlet D, the flanges at this point being omitted topermit free delivery of the liquid from and over the edge or at the sideof the pan. The shutters E E are located between and may slide in thegrooves in the spokes and make contact with the flanges at either sideof the pan, so as to form an inclosure; but these shutters are removablefor the purposeof permitting the cleaning of the pan and form when inplace the sides of a continuous air-duct from the center to the outerend of the spiral pan.

F F is a catchment trough and pipe to receive the evaporated materialand conduct it away from the apparatus to a suitable storage-receptacle.

G is the feed-pipe of the apparatus which connects the feed-tank G withthe chargingtrough end of the pan A This feed-pipe is provided with auniversal joint G in order to permit the unilocular pan to revolve.

H H are air-inlet ducts located on each side of the machine. Theytelescope loosely inside of the hubs B B, but have no direct rigidconnection therewith. The air-exit is located at the outer end of theevaporatingchamber between the feed-trough A and the adjoining innerspiral portion or body.

The operation of the evaporator may be described as follows: Power beingapplied to one or both of the axles O in the proper manner, theunilocular pan A is caused to revolve in the direction indicated by thearrow at the top of Fig. 2 through frictional contact between thecar-wheels O and the hubs B B, the speed of rotation being regulated tocorrespond with the amount of evaporation to be accomplished. Thesupplytank G which is preferably of size double the maximum singlecharge of the apparatus, is placed on a level with the axis and centerof the apparatus, so that with the feed-valve Gr open the liquid willnot begin to run into the trough A until in its downward revolution ithas reached a point on the horizontal diameter of the apparatus. Theliquid then begins to flow into the trough A through a perforated pipelocated therein and is held therein until the trough has reached thelowest point of its revolution, after passing which it begins todischarge its liquid contents by gravity action, and the liquidcontinues to feed and at the same time flow down on the inner surface ofthe outer spiral of the pan from the perforated pipe in the feed-troughuntil the latter has reached the point shown in Fig. 2, when the liquidwill cease to flow through the feed-pipe, the feed-trough having reachedthe level of the supply-tank. The charge thus delivered to the machinealways seeks and tends to remain under control of gravity in the lowestpoint or part of spiral of the pan, the concave surface of the pantaking therefrom by adhesion a continuing film of liquid as theapparatus revolves. The successive charges, however, remaining bygravity at and near the lowest points of the spiral progressively andcontinuously, but in diminishing volume, flow from the outer to theinner end of the spiral, gaining one spiral at each revolution, so thattheoretically the apparatus as illustrated in the drawings will requireseven revolutions in order to send the charge from the outer or chargingend of'the spiral toits inner ordischarging end. At each successiverevolution of the apparatus a new charge is delivered into the outer endof the spiral pan, and this charge passing over the same surface washesoff the film left by the previous charge, leaving another film in itsstead, this operation continuing and being repeated indefinitely as theapparatus is revolved. Simultaueouslywith the introduction of the firstliquid charge and continuously thereafter air is forced into theevaporatingpan and chamber through the air-ducts H H at sufficientpressure toinsure ahigh velocity and am temperature suitable to the workto be performed. The two currents of air entering from the oppositesides of the apparatus and meetingin the center thereof aredefiected,and changing their direction together follow the unilocularchamber formed by and between the spiral pan-surfaces and the shutters EE, the air-current being continually diverted from its natural straightcourse by the concave surface of the pan, and thereby being brought intointimate frictional contact with the liquid film spread thereon, fromwhich, owing to its absorptive nature, the air takes up and carries awayin its course the water content of the liquid so absorbed and eventuallypasses out of the machine with its load of moisture. Necessarily,therefore, as the liquid charges progress from the outer to the innerspiral their bulk is greatly lessened and their density increased. Thisprogressive increase in density, however, takes place coincidently withthe progressively-decreasing pe ripheral speed of the continuous innersurface of the concave spirals,which diminished speed gives time for theaction of gravity to overcome the increasing viscidity of the liquidunder treatment and to spread the liquid over the entire concave spiralsurface of the pan. The rapid current of air impinging sharply againstthe concave surface of the pan or of the liquid film spread thereonserves to break up the air film or layer on the surface of the liquidfilm and also to prevent any particles of the liquid from leaving thefilm and filmsurface in the form of drops or otherwise, the tendencyeverywhere being to force the liquid back against and keep it spreadupon the surface of the pan by the air pressure and current.

While I preferably force the air through the apparatus from the inner tothe outer point, discharging it into a chamber surrounding theapparatus, it is also possible in my invention and in some cases may bedesirable to induce a current of air through the apparatus by exhaustingthe air from the outer end of the pan and from the surrounding chamberinstead of forcing the air into the spiral chamber from the center ofthe apparatus. Then this is done, it gives a current of induced air inthe apparatus which has an entirely different method of action, contact,and effect. When the air is forced in and through the spiral chamber, ittakes effect more directly upon the concave spiral surface of thechamber; but when it is induced it takes effect more directly upon theconvex side and surface of the pan, gliding along that surface, and inthat case if the air be heated to a relatively high temperature it willact as an evaporating medium, acting through the bottom of the pan andon the under side of the filmnamely, that adhering to the concave sideof the pan-surface. For some liquids this may be not only a suitable buta more desirable method of treatment. 1 do not, therefore, confinemyself to forcing air through the apparatus, but may use the inducedcnrrentinstead. In this way by the mere change from the use of a forcedto the use of an induced current of air I am able to evaporate either byabsorption from the surface of the liquid film or by evapora tionthrough heat communicated to the film through the metal surface uponwhich it is spread.

The method of controlling this apparatus during its operation is verysimple. It consists in regulating the amount of each successive liquidcharge in proportion to the speed of rotation and capacity of theevaporating medium and in proportion to the original density of theliquid being treated and the desired density after evaporation. In allcases the rotation of the pan need be only rapid enough to insure theliquidity of the film to a suflicient extent to admit of its being actedupon or mingled with subsequent charges and making proper exit.

My invention in addition to its use as an evaporator may also be usedfor the rapid cooling of liquids by means of cold-air currents forced orinduced through the apparatus for charging liquids with various gases,and also for otherwise changing the chemical nature of liquids throughan air-current acting as a vehicle for chemical elements or compounds.The number of spirals may be changed to any desired number.

I claim as my invention- 7 1. An evaporator forliquid compoundsconsisting of a rotating body composed of a unilocular pan, spirallyprojected or formed, with closed sides, forming a continuous spiralair-duct for the passage of the evaporating medium, supported in ahorizontal and easily-revoluble position, substantially as described.

2. An evaporator for liquid compounds consisting of a rotating body,composed of a unilocular pan, spirally projected or formed, suspendedand held by and between hollow hubs with radiating spokes attachedthereto and removable shutters fitted between the spokes, supported in ahorizontal and easily-revoluble position upon cradles formed of flangedwheels, axles, and journals, substantially as described.

3. An evaporatorforliquidcompoundsconsisting of a horizontal, rotating,unilocular pan, spirally projected or formed, suspended and held by andbetween hollow hubs with radiating spokes attached thereto, removableshutters fitted between the spokes, forming a continuous spiral air-ductfor the passage'of the evaporating medium, the whole rigidly connectedtogether to form a single member supported in an easily-revoluble mannerupon cradles formed of flanged wheels, axles and j ournals,substantia1lyas described.

4. An evaporator for liquid compounds consistin g of a horizontalrotating unilocular pan, spirally projected or formed, suspended andheld by and between hollow hubs with radiating spokes attached thereto,removable shutters fitted between the spokes forming a continuous spiralair-duct for the passage of the evaporating medium, the whole rigidlyconnected together to form a single member, supported in aneasily-revoluble manner upon cradles formed of flanged wheels, axles andjournals, substantially as described, in combination with means forconducting the liquid compound to be evaporated from the source ofsupply to a feed-trough at the outer end of the pan, whereby the liquidis permitted to flow onto and over the concave surface of the spiral pancontinuously by charges.

5. An evaporator for liquid compounds consisting of a horizontal,unilocular pan, spirally projected or formed, suspended and held by andbetween hollow hubs with radiating spokes attached thereto, removableshutters fitted between the spokes forming a continuous spiral air-ductfor the passage of the evaporating medium, the whole rigidly connectedtogether to form a single member, supported in an easily-revolublemanner upon cradles formed of flanged wheels, axles and journals,substantially as described, in combina tion with the means for rotatingthe spiral pan, whereby the liquid being continuously charged into thepan is caused to develop a film of the liquid over and upon the inner,concave surfaceof the pan, progressively and in the same direction fromthe outer or charging end of the pan to the inner or discharging end,substantially as described.

6. An evaporator forliquid compounds consisting of a horizontal,unilocular pan, spirally projected or formed, suspended and held by andbetween hollow hubs with radiating spokes attached thereto, removableshutters fitted between the spokes forming a continuous spiral air-duetfor the passage of the evaporating medium, the whole rigidly connectedtogether to form a single member, supported in an easily-revolublemanner upon cradles formed of flanged wheels, axles and journals,substantially as described, in combination with the means for rotatingthe spiral pan, whereby the liquid being continuously charged into thepan is caused to'develop a film of the liquid over and upon the inner,concave surface of the pan, progressively and in the same direction fromthe outer or charging end of the pan to the inner or discharging end,substantially as described, and with means for conducting theatmospheric air or other evaporating medium at high velocity to and intothe center of the apparatus and through the spiral air-duct over andupon the exposed surface of the liquid film, substantially as described.

7. An evaporator for liquid compounds consisting ofa horizontal,unilocular pan, spi rally projected or formed, suspended and held by andbetween hollow hubs with radiating spokes attached thereto, removableshutters fitted between the spokes forming a continuous spiral air-ductfor the passage of the evaporating medium, the whole rigidly connected.

together to form a single member, supported in an easily-revolublemanner upon cradles formed of flanged wheels,-axles and journals,substantially as described, in combination with the means for rotatingthe spiral pan, whereby the liquid being continuously I through thespiral air-duct over and upon the charged into the pan is caused todevelop a exposed surface of the liquid film, substanfilm 0f the liquidover and upon the inner, tially as described, and also in combinationconcave surface of the pan, progressively and with the means forcarrying away the par- 5 in the same direction from the outer orchargtially-condensed liquid.

ing end of the pan to the inner or discharging end, substantially asdescribed, and with ELTON SHAW means for conducting the atmospheric airor 'Witnesses: other evaporating medium at high velocity to EDWARD S.BERRALL,

10 and into the center of the apparatus and JAMES A. SKILTON.

